No, it's even dumber.

Somehow, the volcanic gasses bubbling up through the lake bed dropped the pH of the lake water enough that it not only became acidic, but literally acid. This technically CAN happen in real life, but it would take much, much longer than represented in the movie and the acid certainly wouldn't eat through a boat bottom or propeller.

Her death is doubly stupid since they could have used some items in the boat as paddles or even wrapped a thick layer of clothing around their hands and paddled the remaining eight or so feet to safety. She certainly didn't have to hop out into the waist-high water and push the boat to shore.

But then we wouldn't have missed out on this fine dramatic performance.

Or we WOULD have missed out on it, rather.